feat(post-form): require 1–6 photos per entry

Raise the FilePond limit from 4 to 6 and enforce a minimum of one photo.
The photo field is first in the form, so initValidation checks it first: an
empty picker blocks submit, reveals the (possibly collapsed) photo section,
and shows "Add at least one photo." under its header. Labels updated to
"Photos (1–6)".

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

themes/intotheeast/js/src/post-form.js

@@ -120,7 +120,7 @@ function buildPhotoCollapse() {
     details.open = true;
     var summary = document.createElement('summary');
     summary.className = 'photos-collapse__summary';
-    summary.textContent = 'Photos (max 4)';
+    summary.textContent = 'Photos (1–6)';
     details.appendChild(summary);
 
     // Relocate the existing control (+ label/status) into the details body.
@@ -188,7 +188,7 @@ function initPhotoConversion() {
             collapse.summary.textContent = '✓ ' + total + ' photo' + (total > 1 ? 's' : '') + ' ready — tap to review';
             collapse.details.open = false;         // auto-collapse when settled
         } else {
-            collapse.summary.textContent = 'Photos (max 4)';
+            collapse.summary.textContent = 'Photos (1–6)';
             collapse.details.open = true;
         }
     }
@@ -469,11 +469,40 @@ function initValidation() {
         el.parentNode.insertBefore(err, el.nextSibling);
     }
 
+    // At least one photo is required. The picker is first in the form, so if it
+    // is empty this is the first invalid field — reveal the (possibly collapsed)
+    // section, show the message under its header, and return an element to
+    // scroll to. Uses the same .field-error class so clearErrors() cleans it up.
+    function showPhotoError(msg) {
+        var collapse = form.querySelector('.photos-collapse');
+        var host, anchor;
+        if (collapse) {
+            collapse.open = true; // reveal the drop zone + message
+            anchor = collapse.querySelector('.photos-collapse__summary');
+            host = collapse;
+        } else {
+            host = document.querySelector('.filepond-root, .form-input-file');
+            anchor = host;
+        }
+        if (!anchor) return host || null;
+        var err = document.createElement('span');
+        err.className = 'field-error';
+        err.textContent = msg;
+        anchor.insertAdjacentElement('afterend', err);
+        return host || anchor;
+    }
+
     // Bubble phase: runs after initEditor's capture-phase codemirror.save(), so
     // the content textarea already holds the live value.
     form.addEventListener('submit', function (e) {
         clearErrors();
         var firstInvalid = null;
+
+        // ≥1 photo (photos are the first field). Count any present FilePond item.
+        if (document.querySelectorAll('.filepond--item').length < 1) {
+            firstInvalid = showPhotoError('Add at least one photo.');
+        }
+
         Object.keys(REQUIRED).forEach(function (name) {
             var el = field(name);
             if (el && !String(el.value).trim()) {
@@ -483,7 +512,7 @@ function initValidation() {
         });
         if (firstInvalid) {
             e.preventDefault();
-            firstInvalid.focus();
+            if (typeof firstInvalid.focus === 'function') firstInvalid.focus();
             firstInvalid.scrollIntoView({ behavior: 'smooth', block: 'center' });
         }
     });